function doPostBackAsync( eventName, eventArgs )
{
    var prm = Sys.WebForms.PageRequestManager.getInstance();

    if ( !Array.contains( prm._asyncPostBackControlIDs, eventName) )
    {
        prm._asyncPostBackControlIDs.push(eventName);
    }
 
    if ( !Array.contains( prm._asyncPostBackControlClientIDs, eventName) )
    {
        prm._asyncPostBackControlClientIDs.push(eventName);
    }
 
    __doPostBack( eventName, eventArgs );
}

function updateChart(controlId,eventArgs)
{
	doPostBackAsync("Panel1",controlId+"$"+eventArgs);
}